Rate constants for the gas-phase reactions of ozone with unsaturated alcohols, esters, and carbonyls

✍ Scribed by Daniel Grosjean; Eric Grosjean; Edwin L. Williams II

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 597 KB
• Volume: 25
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550250909

✦ Synopsis

The kinetics of the gas-phase reaction of ozone with unsaturated alcohols, carbonyls, and esters in air have been investigated at atmospheric pressure, ambient temperature (285-295 K), and in the presence of sufficient cyclohexane to scavenge the hydroxyl radical which forms as a product of the ozone-unsaturated compound reaction. The reaction rate constants, in units of lo-'* cm3 molecule-1 s-', are 0.26 t 0.05 for acrolein, 1.07 ? 0.05 for 2-ethyl acrolein, 6.0 2 0.4 for ethyl vinyl ketone, 4.9 t 0.4 for 3-buten-1-01, 14.4 t 2.0 for ally1 alcohol, 105 t 7 for cis-3-hexen-1-01, 7.5 t 0.9 for methyl methacrylate, 2.9 t 0.3 for vinyl acetate, 4.4 * 0.3 for methyl crotonate, and 8.1 t 0.3 for the 1,l-disubstituted alkene 2-ethyl-1-butene. Substituent effects on reactivity are discussed by comparison with alkenes and indicate that the reactivity of unsaturated alcohols is the same as that of alkene structural homologues and that the -C(O)OR, -C(O)R, and -CHO groups decrease the reactivity towards ozone as compared to alkyl groups. Estimates are made of the atmospheric persistence of these unsaturated compounds using the kinetic data obtained in this study as input to structure-reactivity and linear free-energy relationships.